Volume 432, Number 1, March II 2005
|Page(s)||1 - 14|
|Published online||22 February 2005|
Multi-density model of the ionised gas in NGC 253 using radio recombination lines*
Institut d'Astrophysique de Paris, 98 bis boulevard Arago, 75014 Paris, France
2 Raman Research Institute, C.V. Raman Avenue, Sadashivanagar Post Office, Bangalore 560080, India
3 Joint Astronomy Program, Department of Physics, Indian Institute of Science, Bangalore 560012, India
4 National Radio Astronomy Observatory, PO Box O, Socorro, NM 87801, USA e-mail: firstname.lastname@example.org
Accepted: 26 October 2004
We have imaged the H92α (8.3 GHz), H75α (15 GHz), and H166α (1.4 GHz) Radio Recombination Lines (RRLs) from NGC 253 at resolutions of 4.5 pc (0.4″) , 2.5 pc (0.2″) and 53 pc (4.5″) respectively. The H92α line arises from individual compact sources, most of which possess radio continuum counterparts. The line widths range from ~200 km s-1 for the sources near the radio nucleus to 70–100 km s-1 for the extranuclear ones. These lines are emitted by gas at a density ~104 cm-3. The remainder of the cm-wave RRLs arise in lower density gas (~500 cm-3) with a higher area filling factor and with ten times higher mass. A third component of higher density gas (>104 cm-3) is required to explain the mm-wave RRLs.
Key words: galaxies: individual: NGC 253 / galaxies: ISM / galaxies: starburst / radio lines: galaxies / radio lines: ISM
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.